A word that is part of the wider Germanic vernacular. It's spelled the same in most of the other West Germanic languages (though English, Scots, and Saterland Frisian seem to be the only ones that capitalizes it), except German where it's spelled "Gott." In North Germanic languages, it's generally spelled "guþ/guð", which would be rendered as "guth" in English's surviving Roman letters; the exception being Danish where it's spelled "gud". There's also the Lombardic word "Godan", which is their name for Woden. I'm honestly not sure how that fits in, if at all, but it's still pretty neat.
According to Wiktionary, the Proto-Germanic word was *
gudą, which probably meant more or less what it means now, but the Proto-Indo-European source is
*ǵʰuto, meaning two things: "invoked", and "poured." That word also gave us the Ancient Greek word
khutós or "poured", "piled", "liquid", "washed up"; the Sanskrit word
hótṛ, or "priest who makes a sacrificial (particularly burnt) offering/invokes the Gods during such a ritual"; and Persian word
zowr, or "libation."
(In case anyone's wondering, the word "god" is completely unrelated to the word "good.")
This ... disparity tells me that the word has always been pretty nebulous in exact meaning, though perhaps not as much as it is now. It seems to largely refer to offerings, or the ones who make said offerings. Only in the Germanic languages did this word seem to replace the one generally preferred for such beings in Indo-European languages, which Modern English uses the Latin "deity" for, but which might more natively have been "tiw" or "tue." Incidentally, Old Norse had a word,
goði ("gothi"), which referred to heathen priests. Wiktionary doesn't list an etymology further back, but I do find it interesting, and wonder if this is the "proper" meaning (if such a thing can exist) of the word "god": a priest.
Then of course there's the Gothic (Eastern Germanic) peoples. How do they fit in with that name?